SSO

SAML and SSO: Key Differences and Implementing SSO with SAML

What Is Single Sign-On?

Single sign-on (SSO) is a user authentication process that enables users to access multiple applications and services with a single set of login credentials. The purpose of SSO is to simplify the user experience and improve security by reducing the number of times that users must enter their credentials. This is often the case in most B2B settings today, where dozens of SaaS apps need to be accessed on a daily basis.

For example, consider a user who needs to access multiple applications, such as their email apps, task management tools, automation software, productivity solutions, company portal, and more. With SSO, users can enter their login credentials once, and then have access to all of these applications without having to enter their credentials again. 

This saves time and effort as they only need to remember one set of login credentials, while also reducing the risk of password fatigue. Without SSO, users often choose weak passwords or reuse passwords across multiple applications.

Additionally, SSO can improve security by reducing the number of times that users must enter their passwords, reducing the risk of password theft. Changes to the user’s information or permissions can be made in one central location and automatically apply to all of the applications that the user can access.

What Is SAML?

Security Assertion Markup Language (SAML) is a standard for exchanging authentication and authorization data between an identity provider (IdP) and a service provider (SP). The purpose of SAML is to provide a secure and standard way for organizations to manage user authentication and authorization across multiple systems and applications.

For example, consider a user who needs to access an application provided by a service provider. The user attempts to access the application and is redirected to the IdP for authentication. The IdP verifies the user’s credentials and generates a SAML assertion, which contains information about the user’s identity and attributes. The IdP then sends the SAML assertion to the SP, which uses it to grant the user access to the application.

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How Are SAML and SSO Related?

SAML and SSO are closely linked because SAML provides the framework that enables SSO functionality in many environments. While SSO describes the overall concept of single authentication for multiple systems, SAML is one of the most commonly used standards to achieve this. 

Here’s how they intersect:

  1. SAML as the backbone of SSO: SAML enables secure transmission of identity information between the IdP and SP, which is critical for SSO. The SAML assertions generated during the authentication process carry the user’s identity information needed for SSO.
  2. Complementary benefits: SAML ensures that the data exchanged during the SSO process is standardized. Together, SAML and SSO enhance user convenience and improve security by reducing password reuse and exposure.
  3. Widespread integration: While OAuth/OIDC is often the preferred choice in modern systems, many SSO implementations still rely on SAML as it’s been battle tested in real-world scenarios for quite some time. This makes it a popular consideration for organizations seeking robust authentication solutions.

How Does SAML Work?

SAML operates through an exchange of messages between three main entities: the user (or principal), the IdP, and the SP. The process is designed to authenticate users securely and transfer their identity information across systems without requiring separate logins. Here’s how it works step-by-step:

  1. User authenticates or attempts to access a service: The user can start from the IdP or with the SP. When a user starts at the SP, instead of requesting credentials directly, the SP redirects the user, via an authentication request, to an IdP that handles authentication.
  2. Authentication request: The SP sends a SAML authentication request to the IdP. This request typically includes details about the SP and the requested access level.
  3. Identity verification: The IdP authenticates the user, usually by prompting them to enter their login credentials or verifying a session if they are already logged in.
  4. SAML assertion creation: Upon successful authentication, the IdP generates a SAML assertion. This assertion is an XML-based document containing details about the user’s identity, such as their name, email address, and access permissions.
  5. Assertion delivery: The IdP securely sends the SAML assertion back to the SP, either directly or via the user’s browser, using a secure protocol like HTTPS.
  6. Access granted: The SP validates the SAML assertion and extracts the user’s identity information. If the assertion is valid and the user has the required permissions, the SP grants access to the requested service.

This process ensures secure authentication and enables seamless user transitions across multiple applications without requiring additional logins.

SAML vs. SSO: What Are the Differences? 

1. Scope

SAML operates as a specific protocol designed to standardize the exchange of authentication and authorization data between IdPs and SPs. It defines a precise framework for how identity assertions are structured, transmitted, and validated. 

SAML’s scope is focused narrowly on enabling secure communication between different entities, particularly in environments where systems from multiple organizations need to interact. Its standardized nature ensures interoperability across diverse platforms, making it a go-to solution in enterprise settings.

SSO, in contrast, is a much broader concept. It encompasses any approach or technology that allows users to authenticate once and gain access to multiple systems or services without re-entering their credentials. 

While SAML is one of the protocols that can implement SSO, other standards, such as OAuth, OpenID Connect, or even proprietary mechanisms, can also achieve this functionality. SSO is not limited to a single technology but represents a user-centric strategy to streamline authentication across platforms.

2. Focus

SAML’s focus lies in creating a secure, standardized mechanism for exchanging identity and access data. It emphasizes structure and security, with assertions formatted in XML to encapsulate identity details, authentication status, and access permissions. 

This protocol ensures that identity information can be transmitted reliably between IdPs and SPs, even if they are from different organizations. The technical details of SAML prioritize robust data integrity, confidentiality, and interoperability, making it essential in environments where secure, complex, federated identity management is required.

SSO’s focus is primarily on user experience and security. It can be achieved with standardized protocols and technologies, such as SAML or OAuth, to deliver seamless access to multiple applications or systems. SSO ensures that once users authenticate with a trusted identity provider, they don’t need to log in again when accessing other services. 

The goal of SSO is to reduce login friction, enhance productivity, and minimize the risks associated with repeated credential use, such as credential fatigue or insecure password practices.

3. Use Cases

SAML is most commonly used in enterprise and institutional environments where security, scalability, and interoperability are paramount. Typical use cases include corporate intranets, where employees need access to multiple internal tools and services, and partnerships between organizations that require federated access. 

For example, an enterprise using Microsoft Azure Active Directory may use SAML to enable employees to log in seamlessly to third-party SaaS applications like Salesforce, Workday, or Google Workspace. SAML is also popular in academic settings, where university systems rely on federated authentication to allow students and staff access to shared resources across institutions.

SSO, with its broader applicability, is widely used in both enterprise and consumer environments. Enterprises use SSO to streamline employee access to internal systems, improving efficiency and reducing helpdesk queries related to password resets. In consumer applications, SSO allows users to log in to multiple connected services with a single set of credentials. 

For example, users of Google accounts can access Gmail, Google Drive, YouTube, and other services without logging in separately. SSO is also leveraged in e-commerce and social platforms, where a unified login improves user experience and engagement.

Implementing SSO with SAML 

There are two types of SSO implementations using SAML: 

  • SP-initiated SSO: The user first attempts to access the application provided by the SP. The SP redirects the user to the IdP for authentication. The IdP verifies the user’s credentials and generates a SAML assertion, which is sent back to the SP. The SP uses the information in the SAML assertion to grant the user access to the application.
  • IdP-initiated SSO: The user first logs in to the IdP and is then able to access the applications provided by the SPs without having to enter their credentials again. The IdP generates a SAML assertion and sends it to the SP, which uses the information in the assertion to grant the user access to the application.

For example, consider a user who needs to access a company portal and their email. The company has set up an IdP and the portal and email are provided by two separate SPs. In an SP-initiated SSO scenario, the user attempts to access the portal and is redirected to the IdP for authentication. 

The IdP verifies the user’s credentials and generates a SAML assertion, which is sent back to the portal. The user is now able to access the portal without having to enter their credentials again. In an IdP-initiated SSO scenario, the user first logs in to the IdP, and then has access to both the portal and their email without having to enter their credentials again.

Implementing SSO with SAML involves the following steps:

  1. Setting up the IdP: The IdP is responsible for verifying the user’s credentials and generating a SAML assertion that contains information about the user’s identity and attributes. The IdP must be set up and configured to support SAML.
  2. Setting up the SP: The SP is the application or resource that the user is trying to access. The SP must be configured to accept SAML assertions from the IdP and to use the information contained in the assertion to grant the user access to the application.
  3. Configuring the SAML connection: The IdP and SP must be configured to communicate with each other using SAML. This involves exchanging metadata between the IdP and SP, which contains information about how to communicate using SAML.

SSO with Frontegg 

Frontegg’s low-code, self-serve SSO solution eliminates delays, enabling seamless integration with protocols like OIDC, SAML, and social logins in minutes—not months.

With a fully customizable login box ready to embed, Frontegg saves developers time and empowers teams to manage identity independently. No tickets, no friction—just effortless identity management that lets your team focus on what matters most.

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